Thermoforming web cutting apparatus

Abstract

A thermoforming web cutting apparatus is provided with a frame with a guide post including a tapered outer surface with increasing cross-sectional dimension toward a closing position, a first support structure with a first cutting die, a second support structure with a second cutting die configured to scissor in intermeshing relation with the first cutting die, and a bushing having a tapered inner surface complementary and reverse to the tapered outer surface on the guide post and adjustable in cross-sectional dimension and configured to guide one of the first support structure and the second support structure for axial reciprocation along the guide post. A method is also provided.

1 . A thermoforming web cutting apparatus, comprising: 
 a frame with a guide post including a tapered outer surface with increasing cross-sectional dimension toward a closing position;    a first support structure with a first cutting die;    a second support structure with a second cutting die configured to scissor in intermeshing relation with the first cutting die; and    a bushing having a tapered inner surface complementary and reverse to the tapered outer surface on the guide post and adjustable in cross-sectional dimension and configured to guide one of the first support structure and the second support structure for axial reciprocation along the guide post.    
   
   
       2 . The thermoforming web cutting apparatus of  claim 1 , wherein the thermoforming web cutting apparatus is a thermoforming trim press.  
   
   
       3 . The thermoforming web cutting apparatus of  claim 1 , wherein the bushing comprises a compressible bushing.  
   
   
       4 . The thermoforming web cutting apparatus of  claim 3 , further comprising a compression collar encompassing the bushing and configured to compress the tapered inner surface of the bushing.  
   
   
       5 . The thermoforming web cutting apparatus of  claim 4 , wherein the bushing comprises a bronze bushing.  
   
   
       6 . The thermoforming web cutting apparatus of  claim 5 , wherein the bushing comprises a plurality of circumferential grooves provided in the inner surface of the bushing.  
   
   
       7 . The thermoforming web cutting apparatus of  claim 6 , wherein the guide post comprises at least one lubrication feed port configured to deliver lubrication between the inner surface of the bushing and the outer surface of the guide post.  
   
   
       8 . The thermoforming web cutting apparatus of  claim 7 , wherein the at least one lubrication feed port comprises an axial lubrication feed port and at least one radially extending lubrication feed port communicating with the axial lubrication feed port.  
   
   
       9 . The thermoforming web cutting apparatus of  claim 1 , further comprising a housing having a circumferential body with a slot provided in the body, the housing configured to support the bushing, and at least one fastener configured to adjustably compress the body to decrease width of the slot in order to compress the bushing about the guide post.  
   
   
       10 . The thermoforming web cutting apparatus of  claim 1 , further comprising a housing configured to compress the bushing and adjust fit-up between the bushing and the guide post.  
   
   
       11 . The thermoforming web cutting apparatus of  claim 10 , wherein the housing comprises a pair of shells configured to mate together in complementary relation about the bushing and at least one fastener configured to draw together the shells to compress the bushing.  
   
   
       12 . The thermoforming web cutting apparatus of  claim 11 , wherein the housing comprises a tapered male thread portion, a plurality of axial slots provided in the tapered male thread portion, and a tapered lock nut having a tapered female thread portion configured to engage in complementary relation with the tapered male thread portion and adjustable with respect to the tapered male thread portion to compress the tapered male thread portion so as to compress the bushing contained therein.  
   
   
       13 . The thermoforming web cutting apparatus of  claim 1 , wherein the tapered outer surface of the guide post complements, in opposed relation, the tapered inner surface of the bushing.  
   
   
       14 . The thermoforming web cutting apparatus of  claim 13 , wherein the bushing comprises at least one axial slot configured to accommodate dimensional changes during compression of the bushing about the guide post.  
   
   
       15 . A web cutting assembly for a thermoforming web cutting press, comprising: 
 a guide post having a forward-tapered outer circumferential dimension; and    a bushing assembly with a bushing having a reverse-tapered inner circumferential dimension and an adjustable support collar for retaining the bushing and adjusting the inner circumferential dimension of the bushing relative to the outer circumferential dimension of the guide post.    
   
   
       16 . The web cutting assembly of  claim 15 , wherein the web cutting assembly is configured for use on a thermoforming web trim press.  
   
   
       17 . The web cutting assembly of  claim 15 , wherein the bushing is made from a ductile material.  
   
   
       18 . The web cutting assembly of  claim 17 , wherein the adjustable support collar is configured to compress the bushing in order to adjust the inner circumferential dimension of the bushing.  
   
   
       19 . The web cutting assembly of  claim 17 , wherein the adjustable support collar comprises a tapered bushing housing having a threaded male portion, a cap ring having a threaded female portion complementary with the threaded male portion of the housing, and a plurality of fasteners configured to affix the cap ring onto the bushing housing.  
   
   
       20 . The web cutting assembly of  claim 17 , wherein the bushing comprises a bronze bushing.  
   
   
       21 . The web cutting assembly of  claim 15 , wherein the guide post comprises at least one lubrication feed port extending through the guide post to deliver lubrication to the outer circumferential dimension of the guide post.  
   
   
       22 . The web cutting assembly of  claim 21 , wherein the at least one lubrication feed port comprises an axial feed port and at least one radial feed port communicating with the axial feed port to deliver lubrication to the outer circumferential dimension of the guide post.  
   
   
       23 . The web cutting assembly of  claim 22 , wherein the bushing comprises an inner circumferential surface including an array of circumferential grooves provided therein for retaining lubrication.  
   
   
       24 . The web cutting assembly of  claim 23 , wherein the bushing comprises a bronze bushing.  
   
   
       25 . The web cutting assembly of  claim 15 , wherein the guide post comprises a frustoconical outer surface.  
   
   
       26 . The web cutting assembly of  claim 25 , wherein the bushing comprises a frustoconical inner surface having an array of circumferential grooves provided therein.  
   
   
       27 . A method for accurately severing thermoformed web material using a thermoforming web cutting apparatus, comprising: 
 providing a web cutting apparatus with a guide post having a tapered outer surface that increases in cross-sectional dimension toward a closing position, a first member with a first cutting die, a second member with a second cutting die configured to scissor with the first cutting die, and a bushing adjustable in cross-sectional dimension and having a tapered inner surface complementary and reverse to the tapered outer surface of the guide post;    positioning the first cutting die in intermeshing relation with the second cutting die proximate the closing position; and    adjusting cross-sectional dimension of the bushing to realize a desired accurate fit-up between the bushing and the guide post.    
   
   
       28 . The method of  claim 27  further comprising moving apart the first member and the second member away from the closing position so as to reposition the bushing along the guide post away from the closing position so as to loosen fit-up between the bushing and the guide post.  
   
   
       29 . The method of  claim 28 , wherein moving the bushing relative to the guide post into a position away from the closing position reduces friction between the bushing and the guide post.  
   
   
       30 . The method of  claim 27 , further comprising reciprocating the first member relative to the second member between open and closed positions.